Letters &amp; Miscellanies

Content Tools

Another Crown Engine Found

Remarkably, yet another Crown engine has surfaced since Doug
Nash wrote about the Crown Motor Works in the April 2002 GEM. Jamie
Coobatis, 34730 Seven Mile Road, Livonia MI 48152-4032, called in
to tell us he has a 1/2 HP Crown that, until recently, he thought
was an Elgin. Jamie sent us some pictures of his Crown, along with
the following e-mail:

'I purchased this engine from my cousin about six years ago.
He bought it at an engine swap meet in Cool Springs, Pa. He was
with a buddy of his and he told me he had to borrow some cash from
his buddy to buy it. His friend wasn't interested in it because
he said he already had one! That's how it came to be named an
Elgin Comet. He then sold it to me as a Comet.'

Jamie also contacted Doug Nash, and here's what Doug had to
say about the photos of Jamie's engine:

'They clearly confirm that you have a genuine Crown 1/2 HP
motor. It looks like its flywheel, fan, carburetor, ignition timer
and engine castings (including base) are all original. I can't
vouch for the originality of the muffler, air-intake filter and
fuel tank (all made from brass); in fact I think they are not
original since my Gramp's surviving literature doesn't
mention anything other than iron for those components. The oiler on
the side of the cylinder and the grease cup on the side of the
crankcase are most likely original, since the original literature
mentions them. The spark plug is the correct vintage and could be
original. As to the all red color of your engine, I doubt that is
original since Gramp was an extremely modest and very conservative
person and would never have painted anything bright red. Remember,
he was a contemporary of Henry Ford, who supposedly told buyers
they could buy his cars in any color they liked, as long as it was
black!'

Talking with Jamie, it turns out the gas tank is not original
and was in fact made from an old fire extinguisher. But, Jamie
clearly has a Crown engine, and he thinks he might know of yet
another that, like his, was thought to be an Elgin Comet. Stay
tuned, the hunt for surviving Crown engines is far from over.
-Editor

Ignition Systems

I enjoyed your excellent article on ignition systems in the
October 2002 edition, and I thought some additional theory would be
helpful, especially to explain the purpose of that mysterious
capacitor (or condenser) that is always wired across the ignition
points.

When the points close, the current through the coil ramps up
until it reaches a constant value (usually several amps), which is
determined by the resistance of the coil primary. When the points
open, the energy that has been stored in the magnetic field of the
coil flows into the capacitor, which charges to a voltage several
times higher then the original battery voltage. The current then
reverses and the energy flows back into the coil. This oscillation,
called 'ringing,' produces an AC voltage across the coil
primary that may reach 75-200 volts.

The secondary winding of the coil has a large number of turns
compared to the primary. The secondary multiplies this AC voltage
several hundred times and provides the 20-30,000 volts that
initiate the arc at the spark plug. The purpose of the capacitor is
to form a resonant 'tank' circuit that produces a burst of
AC voltage that is much higher than the battery voltage and has a
relatively long duration. This voltage is, in turn, multiplied a
second time by the coil turns ratio and then fires the plug. If the
capacitor is not present, the energy stored in the coil is
instantly transferred to the plug, and the resulting spark is
extremely short and ineffective for ignition.

Project Update: In case anyone doubted whether Chester
Leighton's 'Mini McCormick' could pull its own weight,
Chester sent this photo of his creation plowing his daughter's
garden. Chester wrote about the IHC LA-powered tractor in the
September GEM.

This double step-up explains why it is a good idea to replace
the capacitor when changing points. The capacitor can appear okay
when checked for shorts with a multi-meter, but it may break down
at 100 volts or so. It also explains why an ignition system can act
up in damp weather even when the spark plug and its wires are dry.
Moisture is not a problem at 6 or 12 volts, but since 75-200
appears across the points, moisture in the coil primary circuit can
sometimes provide a resistive path that will permit enough leakage
current to reduce the spark output.

Steam Turbine

GEM reader David Newman is looking for a home for a 1933 De
Laval steam turbine that's been helping supply power since 1952
at a paper mill in the Philadelphia, Pa., area.

David says a local trade school has expressed interest in the
unit, but he wants to see the turbine go to a museum or an
organization that will set it up for display. He's not
interested in seeing it go to a private collection.

It's situated under a crane way, and it can be split into
three parts and loaded onto a flatbed in the building where it
currently sits.

The Square Deal Subscription Program is designed as a paperless transaction with automatic renewals at a preferred low rate. With advanced electronic notification, a 100% satisfaction guarantee and an easy opt-out plan, the Square Deal Subscription Program is the best value, risk free, eco-friendliest way to subscribe.